Sri Lanka's opposition looks headed for a surprisingly strong win as counting continues following one of the country's most violent elections. Authorities have extended a nationwide curfew to Friday morning. Election officials may order repolling in some areas.

The opposition United National Front looked set to achieve a significant victory in Sri Lanka's parliamentary elections as counting continues under an extended nationwide curfew.

Final results will be delayed until late Friday, after election officials decide whether to order a fresh vote in some areas affected by violence and other irregularities. Sri Lanka's election commissioner Dayananda Dissanayake said counting has been halted in at least two districts affected by violence.

Analysts still said no individual group will win a clear majority in the country's 225-seat legislature. But with President Chandrika Kumaratunga's People's Alliance lagging behind in almost all the districts counted so far, most observers believed the opposition will easily muster a majority with support from its Tamil and Muslim political allies.

Several of Sri Lanka's minority Tamil parties contested as a group this year and they are expected to make significant gains. For Sri Lanka's Tamil population, the main election issue is finding an end to the island's 18 year long war with Tamil separatists. Opposition leader Ranil Wickeremesinghe promised to find a negotiated settlement to the conflict, which has claimed over 64,000 lives. President Kumaratunga's attempts at negotiation, most recently through a Norwegian initiative this year, have failed to end the fighting.

Independent election monitors are also calling for a re-poll in predominantly Tamil areas in the north and east of the island where they said army blockades prevented 130,000 Tamils from reaching the polls.

The expected opposition win may not bring the island much needed political stability. President Kumaratunga will remain in office for another five years and she holds the power to suspend parliament at any time. Analysts said she will have to cooperate with an opposition-led parliament in order for Sri Lanka to escape a cycle of political instability.

Wednesday's polls, the second in just 14 months, followed a violent election campaign. Over 60 people have died in election-related violence so far.